Background Patients with systemic lupus erythematosus (SLE) have an increased risk of preeclampsia (PE), which can be confused with lupus nephritis.
Objectives Our objective was to evaluate the behaviour of mean pulsatility index in the uterine arteries (mPI-UtA), sFlt-1/PlGF ratio and endoglin levels in pregnant women with SLE and/or antiphospholipd syndrome (APS).
Methods Pregnant women with SLE and/or APS attending our high-risk pregnancy unit were consecutively included. Clinical, analytical and sonographic evaluations were conducted at baseline, at different weeks (wk) of gestational age (10-13, 22, 28, 32), at delivery and postpartum. We collected demographic data, information regarding cardiovascular risk factors and toxic habits, the underlying disease, obstetrical history, last SLE flare, previous and current treatments, as well as usual blood tests including complement and a-dsDNA antibodies levels. Levels of sFlt-1, PlGF, and maternal serum endoglin were quantified by ELISA. PE and its severity were diagnosed according with the ISSSHP definition. Intrauterine growth restriction (IUGR) was defined as a small for gestational age newborn together with a Doppler PI in the umbilical artery above the 95th percentile.
Results 34 consecutive patients were recruited, of whom 29 had SLE (4 with secondary APS), 3 had primary APS and 2 had antiphospholipid antibodies but without clinical criteria for APS. Five patients have not delivered at the time of writing and we missed 1 patient in the follow-up. Ten patients (36%) suffered an early pregnancy loss (<12 wks), being most frequent among patients with previous APS diagnosis (p=0.03), high blood pressure (p=0.01), arterial thrombosis related to APS (p=0.03), and the presence of lupus anticoagulant (p=0.004). In uneventful pregnancies the values of the studied markers were within normal limits for the gestational age throughout pregnancy. One SLE patient (5.6%) had mild PE after 32 wk together with IUGR. We observed a relationship between IUGR and higher SLEDAI both before and throughout pregnancy (baseline, p=0.01; 10-13 wks, p=0.04; 22 wk, p=0.02; 28 wk, p=0.05; 32 wk, p=0.01). IUGR was also associated with higher mPI-UtA at 22 wk (p=0.05). Endoglin levels (14.6 ng/ml vs <7.9, 26.9 vs <7.2, 49 vs <13.6, at 22 wk, 28 wk and 32 wk, respectively) and ratio curve sFlt1/PlGF (17 vs 14.8, 36.6 vs 16.9, 170.7 vs 86.4 at 22 wk, 28 wk and 32 wk, respectively) behaved abnormal in this case. Among remaining patients, 1 patient with SLE (5.6%) developed HBP before delivery, 1 SLE patient had premature rupture of membranes at term, and 3 SLE patients had a preterm delivery at 28, 32 and 36 wks, respectively. 12 patients (67%) had a mild exacerbation of SLE, and only 1 (8%) had moderate activity requiring high doses of corticosteroids and azathioprine.
Conclusions Our preliminary results indicate that mPI-UtA, sFlt1/PlGF ratio and endoglin levels behave in patients with SLE and/or APS essentially as in the general population. Moreover, these markers may be useful to predict the onset of PE in women with SLE and to make the differential diagnosis between PE and an episode of lupus activity.
Disclosure of Interest None declared